Coscinodiscus wailesii

Division:

Bacillariophyta

Class:

Coscinodiscophyceae

Order:

Coscinodiscales

Species name:

Coscinodiscus wailesii Gran & Angst

Synonyms:

None known

Common name:

A centric diatom

Date of introduction and origin

Coscinodiscus wailesii was first detected in the
English Channel in 1977 (as Coscinodiscus nobilis Grunow)
and is thought to originate from the Indian and Pacific Oceans
(Boalch & Harbour 1977; Boalch 1987; Wallentinus in
press).

Method of introduction

Unknown method of introduction, but ballast water transport
cannot be ruled out and importation with oysters has been
hypothesised as another potential vector (Rincé & Paulmier
1986; Wallentinus in press).

Reasons for success

Unknown.

Rate of spread and methods involved

It spread rapidly and was recorded from the English Channel
(near Plymouth, Devon) in 1977; Atlantic coast of France by 1978
and Norway by 1979 (Hasle 1990; Wallentinus in press).

Distribution

It is found in the English Channel, Atlantic coast of France,
Frisian Islands, Helgoland and Norway (Rincé & Paulmier 1986;
Wallentinus in press).

Factors likely to influence spread and distribution

Unknown.

Effects on the environment

It can reach high numbers and produce copious mucilage which
'in sinking' can accumulate insoluble skeletons of planktonic
organisms and mineral particles, increasing its volume and density
(Boalch & Harbour 1977) and blanket the seabed.

Effects on commercial interests

Fishing trawls may become clogged or broken by heavy grey
slime. It may interfere with the hauling of fishing gear and
prolonged washing or air drying may not completely remove it
(Boalch & Harbour 1977).

Control methods used and effectiveness

None used.

Beneficial effects

None known.

Comments

Boalch (1987) reported Coscinodiscus wailesii to be
still present in the Plymouth area and to have become a major
constituent of the winter centric diatom population.

References

Boalch, G.T. 1987. Changes in the phytoplankton of the western
English Channel in recent years.